SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f92bd47385c9588b411b768192393f083b4c83f9d6f3273aa15dbcbd8f4de4b0' 
  AND token = 'Bgt4HSFJnQ7wUoBtxpfBlaQy9RQIoyzG9LWOXsGiCz0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}